smbios: Unmap memory on error on identify

[olce]

Summary

While here, de-indent most of the code by simply bailing out if 'addr'
is still 0 after the various detection methods have been tried.

Sponsored by: The FreeBSD Foundation

[emaste]

👍 for the early return

sys/dev/smbios/smbios.c

149

I recommend leaving the "unnecessary" braces around this statement -- at least, the if and else blocks are now both a single statement and should be consistent.

[imp]

+1 for ed's comment other wise looks good.

[olce]

sys/dev/smbios/smbios.c

149

I've removed the braces around the "then" part (not updated now here, but will be at commit).